U.S. patent application number 15/130059 was filed with the patent office on 2017-10-19 for electrical switching apparatus, and operating mechanism and lever assembly therefor.
This patent application is currently assigned to EATON CORPORATION. The applicant listed for this patent is EATON CORPORATION. Invention is credited to WILLIAM GEORGE EBERTS, KENNETH MARTIN FISCHER, EDWARD ANTHONY PRINCE, FRANK JOSEPH STIFTER, JR., DAVID CURTIS TURNER.
Application Number | 20170301500 15/130059 |
Document ID | / |
Family ID | 60039587 |
Filed Date | 2017-10-19 |
United States Patent
Application |
20170301500 |
Kind Code |
A1 |
STIFTER, JR.; FRANK JOSEPH ;
et al. |
October 19, 2017 |
ELECTRICAL SWITCHING APPARATUS, AND OPERATING MECHANISM AND LEVER
ASSEMBLY THEREFOR
Abstract
A lever assembly is for an operating mechanism of an electrical
switching apparatus. The electrical switching apparatus includes a
number of pairs of separable contacts structured to move from a
CLOSED position to a TRIPPED OPEN position in response to a trip
condition. The operating mechanism has an enclosure member and a
number of biasing elements coupled to the enclosure member. The
biasing elements are structured to move the separable contacts from
the CLOSED position to the TRIPPED OPEN position. The lever
assembly includes a lever member structured to engage the enclosure
member, and a component located on the lever member. The component
is structured to extend through each of the biasing elements in
order to lengthen each of the biasing elements when the separable
contacts are in the CLOSED position.
Inventors: |
STIFTER, JR.; FRANK JOSEPH;
(CORAOPOLIS, PA) ; TURNER; DAVID CURTIS;
(IMPERIAL, PA) ; EBERTS; WILLIAM GEORGE; (MOON
TOWNSHIP, PA) ; FISCHER; KENNETH MARTIN;
(FINLEYVILLE, PA) ; PRINCE; EDWARD ANTHONY;
(ALIQUIPPA, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EATON CORPORATION |
CLEVELAND |
OH |
US |
|
|
Assignee: |
EATON CORPORATION
CLEVELAND
OH
|
Family ID: |
60039587 |
Appl. No.: |
15/130059 |
Filed: |
April 15, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01H 71/525 20130101;
H01H 2235/004 20130101; H01H 71/521 20130101; H01H 71/46
20130101 |
International
Class: |
H01H 71/46 20060101
H01H071/46 |
Claims
1. A lever assembly for an operating mechanism of an electrical
switching apparatus, said electrical switching apparatus comprising
a number of pairs of separable contacts structured to move from a
CLOSED position to a TRIPPED OPEN position in response to a trip
condition, said operating mechanism comprising an enclosure member
and a number of biasing elements coupled to said enclosure member,
said number of biasing elements being structured to move said
number of pairs of separable contacts from the CLOSED position to
the TRIPPED OPEN position, said lever assembly comprising: a lever
member structured to engage said enclosure member; and a component
disposed on said lever member, wherein said component is structured
to extend through each of said number of biasing elements in order
to lengthen each of said number of biasing elements when said
number of pairs of separable contacts are in the CLOSED
position.
2. The lever assembly of claim 1 further comprising a number of
retaining members each coupled to said lever member; and wherein
said component is a pin member engaging each of said number of
retaining members in order to be retained on said lever member.
3. The lever assembly of claim 2 wherein said lever member
comprises a base portion and a number of leg portions; wherein each
of said number of retaining members is coupled to said base
portion; and wherein each of said number of leg portions extends
from said base portion at an angle greater than 90 degrees with
respect to said base portion.
4. The lever assembly of claim 3 wherein said number of leg
portions comprises a first leg portion and a second leg portion
spaced from said first leg portion.
5. The lever assembly of claim 3 wherein said lever member further
comprises a number of rib portions each extending from said base
portion to a corresponding one of said number of leg portions.
6. The lever assembly of claim 2 wherein said number of retaining
members comprises a first retaining member, a second retaining
member, and a third retaining member; wherein said first retaining
member and said second retaining member have a common longitudinal
axis; wherein said component is a pin member disposed parallel to
the longitudinal axis; and wherein said pin member is disposed
between the longitudinal axis and said third retaining member.
7. An operating mechanism for an electrical switching apparatus,
said electrical switching apparatus comprising a number of pairs of
separable contacts structured to move from a CLOSED position to a
TRIPPED OPEN position in response to a trip condition, said
operating mechanism comprising: an enclosure member; a number of
biasing elements coupled to said enclosure member, said number of
biasing elements being structured to move said number of pairs of
separable contacts from the CLOSED position to the TRIPPED OPEN
position; and a lever assembly comprising: a lever member engaging
said enclosure member, and a component disposed on said lever
member, wherein said component extends through each of said number
of biasing elements in order to lengthen each of said number of
biasing elements when said number of pairs of separable contacts
are in the CLOSED position.
8. The operating mechanism of claim 7 wherein each of said number
of biasing elements is structured to move between a FIRST position
corresponding to said number of pairs of separable contacts being
in the CLOSED position, and a SECOND position corresponding to said
number of pairs of separable contacts being in the TRIPPED OPEN
position; wherein each of said number of biasing elements has a
respective distal end portion; wherein, when each of said number of
biasing elements is in the FIRST position, said respective distal
end portion is spaced a first distance from said enclosure member;
wherein, when each of said number of biasing elements is in the
SECOND position, said respective distal end portion is spaced a
second distance from said enclosure member; and wherein the first
distance is greater than the second distance.
9. The operating mechanism of claim 8 wherein said number of
biasing elements comprises a first spring and a second spring each
having a loop portion; and wherein said component extends through
the loop portion of said first spring and the loop portion of said
second spring in order to pull said first spring and said second
spring from the SECOND position toward the FIRST position.
10. The operating mechanism of claim 8 further comprising a pin
member and a handle arm structured to move into and out of
engagement with said pin member; wherein said handle arm is coupled
to said enclosure member; wherein said lever member comprises a
base portion and a number of leg portions each extending from said
base portion at a respective junction; wherein, when said number of
biasing elements move from the SECOND position toward the FIRST
position, said base portion pivots about each respective junction
away from said enclosure member.
11. The operating mechanism of claim 10 wherein said number of leg
portions comprises a first leg portion and a second leg portion
spaced from said first leg portion; and wherein, when said number
of biasing elements move from the SECOND position toward the FIRST
position, said first leg portion and said second leg portion move
into engagement with said pin member in order to cause said base
portion to pivot about each respective junction away from said
enclosure member.
12. The operating mechanism of claim 8 wherein said enclosure
member has a location; wherein, when said number of biasing
elements move between the FIRST position and the SECOND position,
the location rotates in a plane; and wherein said component is a
pin member disposed perpendicular to the plane.
13. The operating mechanism of claim 7 further comprising a handle
arm comprising an interior portion coupled to said enclosure
member; wherein said interior portion has a first distal edge
portion, a second distal edge portion disposed opposite and distal
said first distal edge portion, and a pocket portion extending from
proximate said first distal edge portion to proximate said second
distal edge portion; wherein said lever member comprises a base
portion and a number of leg portions each extending from said base
portion; and wherein said base portion is substantially disposed in
said pocket portion.
14. The operating mechanism of claim 7 wherein said lever assembly
further comprises a number of retaining members each coupled to
said lever member; and wherein said component is a pin member
engaging each of said number of retaining members in order to be
retained on said lever member.
15. The operating mechanism of claim 14 wherein said lever member
comprises a base portion and a number of leg portions; wherein each
of said number of retaining members is coupled to said base
portion; and wherein each of said number of leg portions extends
from said base portion at an angle greater than 90 degrees with
respect to said base portion.
16. The operating mechanism of claim 15 wherein said number of leg
portions comprises a first leg portion and a second leg portion
spaced from said first leg portion.
17. The operating mechanism of claim 15 wherein said lever member
further comprises a number of rib portions each extending from said
base portion to a corresponding one of said number of leg
portions.
18. The operating mechanism of claim 14 wherein said number of
retaining members comprises a first retaining member, a second
retaining member, and a third retaining member; wherein said first
retaining member and said second retaining member have a common
longitudinal axis; wherein said component is a pin member disposed
parallel to the longitudinal axis; and wherein said pin member is
disposed between the longitudinal axis and said third retaining
member.
19. An electrical switching apparatus comprising: a number of pairs
of separable contacts structured to move from a CLOSED position to
a TRIPPED OPEN position in response to a trip condition; and an
operating mechanism comprising: an enclosure member, a number of
biasing elements coupled to said enclosure member, said number of
biasing elements being structured to move said number of pairs of
separable contacts from the CLOSED position to the TRIPPED OPEN
position, and a lever assembly comprising: a lever member engaging
said enclosure member, and a component disposed on said lever
member, wherein said component extends through each of said number
of biasing elements in order to lengthen each of said number of
biasing elements when said number of pairs of separable contacts
are in the CLOSED position.
20. The electrical switching apparatus of claim 19 wherein said
electrical switching apparatus is a molded case circuit breaker.
Description
BACKGROUND
Field
[0001] The disclosed concept relates to electrical switching
apparatus, such as, for example, circuit breakers. The disclosed
concept also relates to operating mechanisms for electrical
switching apparatus. The disclosed concept further relates to lever
assemblies for operating mechanisms.
Background Information
[0002] Electrical switching apparatus, such as circuit breakers,
are employed in diverse capacities in power distribution systems. A
circuit breaker may include, for example, a line conductor, a load
conductor, and a pair of separable contacts including a fixed
contact and a movable contact, with the movable contact being
movable into and out of electrically conductive engagement with the
fixed contact. The fixed contact is electrically conductively
engaged with one of the line and load conductors, and the movable
contact is electrically conductively engaged with the other of the
line and load conductors.
[0003] Upon initial separation of the movable contact away from the
stationary contact, an electrical arc is formed in the space
between the contacts. The arc provides a means for smoothly
transitioning from a closed circuit to an open circuit, but
produces a number of challenges to the circuit breaker designer.
Among them is the fact that the arc results in the undesirable flow
of electrical current through the circuit breaker to the load.
Additionally, the arc, which extends between the contacts, often
results in vaporization or sublimation of the contact material
itself.
[0004] Therefore, it is desirable to extinguish any such arcs as
soon as possible upon their propagation.
[0005] There is thus room for improvement in electrical switching
apparatus, and in operating mechanisms and lever assemblies
therefor.
SUMMARY
[0006] These needs and others are met by embodiments of the
disclosed concept, which are directed to an electrical switching
apparatus, and operating mechanism and lever assembly therefor.
[0007] As one aspect of the disclosed concept, a lever assembly for
an operating mechanism of an electrical switching apparatus is
provided. The electrical switching apparatus includes a number of
pairs of separable contacts structured to move from a CLOSED
position to a TRIPPED OPEN position in response to a trip
condition. The operating mechanism has an enclosure member and a
number of biasing elements coupled to the enclosure member. The
biasing elements are structured to move the separable contacts from
the CLOSED position to the TRIPPED OPEN position. The lever
assembly includes a lever member structured to engage the enclosure
member, and a component located on the lever member. The component
is structured to extend through each of the biasing elements in
order to lengthen each of the biasing elements when the separable
contacts are in the CLOSED position.
[0008] As another aspect of the disclosed concept, an operating
mechanism including an enclosure member, a number of biasing
elements, and the aforementioned lever assembly is provided.
[0009] As yet another aspect of the disclosed concept, an
electrical switching apparatus including a number of pairs of
separable contacts and the aforementioned operating mechanism is
provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A full understanding of the disclosed concept can be gained
from the following description of the preferred embodiments when
read in conjunction with the accompanying drawings in which:
[0011] FIG. 1 is an exploded front isometric view of a portion of
an electrical switching apparatus, and operating mechanism and
lever assembly therefor, shown in the TRIPPED OPEN position, in
accordance with a non-limiting embodiment of the disclosed
concept;
[0012] FIG. 2 is an assembled front isometric view of the portion
the electrical switching apparatus, and operating mechanism and
lever assembly therefor of FIG. 1, shown with portions removed in
order to see hidden structures, and shown in the CLOSED
position;
[0013] FIG. 3 is a front isometric view of the lever assembly of
FIG. 2;
[0014] FIG. 4 is a side elevation view of the lever assembly of
FIG. 3;
[0015] FIG. 5 is a bottom isometric view of a handle arm for the
operating mechanism of FIG. 2;
[0016] FIG. 6 is a bottom isometric view of a prior art handle
arm;
[0017] FIG. 7 is a side elevation view of the electrical switching
apparatus, and operating mechanism and lever assembly therefor of
FIG. 2, shown in the CLOSED position;
[0018] FIG. 8 is an enlarged view of a portion of the electrical
switching apparatus, and operating mechanism and lever assembly
therefor of FIG. 7;
[0019] FIG. 9 is a side elevation view of the electrical switching
apparatus, and operating mechanism and lever assembly therefor of
FIG. 7, shown in the TRIPPED OPEN position; and
[0020] FIG. 10 is an enlarged view of a portion of the electrical
switching apparatus, and operating mechanism and lever assembly
therefor of FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] As employed herein, the term "number" shall mean one or an
integer greater than one (i.e., a plurality).
[0022] As employed herein, the statement that two or more parts are
"connected" or "coupled" together shall mean that the parts are
joined together either directly or joined through one or more
intermediate parts.
[0023] As employed herein, the statement that two or more parts or
components "engage" one another shall mean that the parts exert a
force against one another either directly or through one or more
intermediate parts or components.
[0024] FIGS. 1 and 2 show an electrical switching apparatus (e.g.,
without limitation, molded case circuit breaker 2), in accordance
with one non-limiting embodiment of the disclosed concept. The
example circuit breaker 2 includes a number of pairs of separable
contacts (one pair of separable contacts 4 is shown in simplified
form in FIGS. 1 and 2) and an operating mechanism 10 for opening
and closing the separable contacts 4. The operating mechanism 10
includes an enclosure member 12, a number of biasing elements (two
springs 14,16 are shown in FIGS. 1 and 2) coupled to and being
substantially located within the enclosure member 12, a handle arm
20 coupled to the enclosure member 12, a pin member 40, and a lever
assembly 50. The handle arm 20 moves into and out of engagement
with the pin member 40 during operation of the circuit breaker 2 in
a generally well known manner. The springs 14,16 move the separable
contacts 4 from a CLOSED position to a TRIPPED OPEN position in
response to a trip condition. As will be discussed in greater
detail below, the lever assembly 50 provides a novel mechanism to
lengthen the springs 14,16 when the separable contacts 4 are in the
CLOSED position. In this manner, the springs 14,16 will be able to
cause the separable contacts 4 to trip open significantly faster
than the separable contacts of prior art circuit breakers (not
shown). As a result, electrical arcs caused by the separable
contacts 4 tripping open will advantageously be quenched
significantly faster in the circuit breaker 2 than in prior art
circuit breakers.
[0025] Referring to FIGS. 3 and 4, the lever assembly 50 includes a
lever member 52 structured to engage the enclosure member 12 (FIGS.
1 and 2), a component (e.g., without limitation, pin member 54)
located on the lever member 52 and engaging the springs 14,16
(FIGS. 1 and 2), and a number of retaining members (three example
stud members 56,57,58 are shown) each coupled to the lever member
52. The pin member 54 engages each of the stud members 56,57,58. It
will be appreciated that the force of the springs 14,16 on the pin
member 54, in combination with the force of the stud members
56,57,58 on the pin member 54, retains the pin member 54 on the
lever member 52 in a relatively secure manner. Although the
disclosed concept is being described in association with the stud
members 56,57,58 being employed to retain the pin member 54 on the
lever member 52, it will be appreciated that any suitable
alternative configuration and/or combination of components may be
employed in order to perform the desired function of retaining the
pin member 54 on the lever member 52.
[0026] As shown, the stud members 56,57 have a common longitudinal
axis 59 and the pin member 54 is parallel to the longitudinal axis
59. Additionally, the pin member 54 is located between the stud
member 58 and the longitudinal axis 59. As a result of the
configuration of the pin member 54 and stud members 56,57,58, and
the geometry of the lever member 52, the circuit breaker 2 is
advantageously able to accommodate the lever assembly 50 with
relatively minimal modification.
[0027] More specifically, the lever member 52 has a generally
planar base portion 60 and a number of leg portions (two leg
portions 62,64 are shown) extending from the base portion 60 at an
angle 65 greater than 90 degrees with respect to the base portion
60. The angle 65 advantageously allows the lever member 52 to be
retained in the circuit breaker 2 without modification to internal
components of the circuit breaker 2, as will be discussed below.
The lever member 52 also includes a number of rib portions 66 (and
another rib portion (not shown) for the leg portion 64) each
extending from the base portion 60 and a corresponding one of the
leg portions 62,64 in order to provide support to the respective
leg portions 62,64. As shown, the leg portions 62,64 are spaced
from one another.
[0028] Referring to FIG. 2, the pin member 40 has a first side
portion 42 and a second side portion 44 that are located on
opposing sides of a component 46 of the circuit breaker 2. The
component 46 is coupled to the pin member 40. In operation, when
the separable contacts 4 are in the CLOSED position (FIG. 2), the
leg portion 62 engages the side portion 42, and the leg portion 64
engages the side portion 44. Thus, as shown, the lever member 52
avoids interfering with the component 46. In this manner, the
spacing of the leg portions 62,64 and the angle 65 together allow
the lever member 52 to be maintained within the circuit breaker 2
without modification to the pin member 40 or the component 46.
[0029] Referring to FIG. 5, the handle arm 20 has an interior
portion coupled to the enclosure member 12 (FIGS. 1 and 2). The
interior portion of the handle arm 20 has opposing distal edge
portions 22,24 and a pocket portion 26. The base portion 60 of the
lever member 52 is substantially located in and is coupled to the
pocket portion 26 (see, for example, FIG. 1). By contrast, FIG. 6
shows a bottom isometric view of a prior art handle arm 100. As
shown, the handle arm 100 includes a centrally located rib portion
102. By having the handle arm 20 of the instant invention be devoid
of such a rib portion, and rather include the pocket portion 26
extending from proximate the first edge portion 22 to proximate the
second edge portion 24, the novel handle arm 20 advantageously
accommodates the lever assembly 50. Apart from the novel handle arm
20, the circuit breaker 2 accommodates the lever assembly 50
without requiring undesirable further modification.
[0030] FIGS. 7 and 8 show the circuit breaker 2 with the separable
contacts 4 in the CLOSED position, and FIGS. 9 and 10 show the
circuit breaker with the separable contacts 4 in the TRIPPED OPEN
position. The springs 14,16 are structured to move between FIRST
and SECOND positions corresponding to the separable contacts 4
being in the CLOSED and TRIPPED OPEN positions, respectively. When
the springs 14,16 move from the SECOND position toward the FIRST
position, a given location of the enclosure member 12 will rotate
in a direction (see, for example, direction 32 in FIG. 8) that is
located in a plane. It will be appreciated that the pin member 54
is located perpendicular to the aforementioned plane in order to be
able to lengthen the springs 14,16.
[0031] More specifically, as shown in FIG. 8, the spring 16 has a
loop portion 17 and the pin member 54 extends through the loop
portion 17, a configuration that allows the spring 16 to be
lengthened when the separable contacts 4 are in the CLOSED
position. The loop portion 17 has a distal end portion 19, and in
the FIRST position the distal end portion 19 is spaced a first
distance 30 from the enclosure member 12. Referring to FIG. 10,
which shows the spring 16 in the SECOND position, the distal end
portion 19 is spaced a second distance 31 from the enclosure member
12. In comparing FIGS. 8 and 10, it can be seen that the first
distance 30 is greater than the second distance 31. It will be
appreciated that the pin member 54 likewise extends through a
corresponding loop portion of the spring 14 (FIGS. 1 and 2) in
order to lengthen the spring 14 the same as the spring 16.
[0032] Additionally, the pin member 54 extends through and engages
the loop portions 17 (and the loop portion of the spring 14) in
order to pull the springs 14,16 from the SECOND position (FIGS. 9
and 10) toward the FIRST position (FIGS. 7 and 8). Each of the leg
portions 62 (and the leg portion 64, not shown in FIGS. 7-10)
extends from the base portion 60 at a respective junction. When the
springs 14,16 move from the SECOND position to the FIRST position,
the base portion 60 pivots about each respective junction away from
the enclosure member 12 in order to allow the pin member 54 to pull
the springs 14,16 to the FIRST position. Also, when the springs
14,16 move from the SECOND position toward the FIRST position, the
leg portions 62,64 move into engagement with the pin member 40 in
order to cause the base portion 60 to pivot about the junctions
from which the leg portions 62,64 extend.
[0033] Prior art circuit breakers (not shown), by way of contrast,
employ springs in which distal end portions are spaced
substantially the same distance from enclosure members irrespective
of the position of the separable contacts. Thus, the lever assembly
50 provides a novel mechanism to lengthen the springs 14,16 when
the springs 14,16 are in the FIRST position corresponding to the
separable contacts 4 being CLOSED. The resulting additional tension
that is imparted to the springs 14,16 directly corresponds to an
increase in tripping speed, which provides significant advantages
in terms of arc quenching. Accordingly, the lever assembly 50
allows electrical arcs to be quenched significantly faster in the
circuit breaker 2 than prior art circuit breakers, thereby reducing
the flow of electrical current through the circuit breaker 2. This
improves safety during a trip condition and also prolongs the life
of many components of the circuit breaker 2, including the
separable contacts 4. Furthermore, the lever assembly 50 provides
the aforementioned advantages without requiring different and
stronger springs, which might otherwise impart undesirable stresses
to a circuit breaker.
[0034] Accordingly, it will be appreciated that the disclosed
concept provides for an improved (e.g., without limitation, longer
lasting, safer) electrical switching apparatus 2, and operating
mechanism 10 and lever assembly 50 therefor, in which the lever
assembly 50 provides a novel mechanism to lengthen the springs
14,16 of the operating mechanism 10 when the separable contacts 4
are in the CLOSED position. In this manner, tripping speeds are
significantly increased by virtue of the additional tension in the
springs 14,16. As a result, electrical arcs generated during a
tripping event are advantageously able to be quenched relatively
fast.
[0035] While specific embodiments of the disclosed concept have
been described in detail, it will be appreciated by those skilled
in the art that various modifications and alternatives to those
details could be developed in light of the overall teachings of the
disclosure. Accordingly, the particular arrangements disclosed are
meant to be illustrative only and not limiting as to the scope of
the disclosed concept which is to be given the full breadth of the
claims appended and any and all equivalents thereof.
* * * * *